FIG. 1 is a block diagram of a conventional gas leakage detection system. As shown in FIG. 1, the conventional gas leakage detection system includes a cylinder cabinet (C/C) 1 that receives a cylinder, a gas box 3 that controls flow rate and the like of gas supplied to a process chamber of a semiconductor manufacturing apparatus, a semiconductor manufacturing apparatus housing (M/C) 5 that has the process chamber of the semiconductor manufacturing apparatus, a pump box 7 that has a vacuum pump, a harm eliminating box 9 that has a harm eliminator, exhaust pipes 10 and 24, a gas leakage detector 11 for exhausting a cylinder cabinet housing, a gas leakage detector 13 for exhausting an-apparatus housing, a gas sampling part 15, a gas leakage detector 17 for room atmosphere, a gas leakage detector 19 for exhausting a pump housing, a gas leakage detector 21 for exhausting a harm eliminator housing, and a gas detector 23 for detecting the breakthrough of the harm eliminator.
The cylinder cabinet (C/C) 1 is connected to the exhaust pipe 10, and the gas leakage detector 11 for exhausting the cylinder cabinet housing is connected between the cylinder cabinet (C/C) 1 and the exhaust pipe 10. A gas connecting port of the gas box 3 is connected to the cylinder cabinet (C/C) 1 via a stop valve 2. In addition, an exhaust opening of the gas box 3 is connected to the exhaust pipe 10. The semiconductor manufacturing apparatus housing (M/C) 5 is connected to the exhaust pipe 10. The gas leakage detector 13 for exhausting the apparatus housing is connected between the gas box 3 and the semiconductor manufacturing apparatus housing (M/C) 5, and the exhaust pipe 10.
A vacuum pump admission port of the pump box 7 is connected to the semiconductor manufacturing apparatus housing (M/C) 5, and an exhaust opening is connected to the exhaust pipe 24. The gas leakage detector 19 for exhausting the pump housing is connected between the pump box 7 and the exhaust pipe 24. Additionally, a vacuum pump exhaust connecting port of the harm eliminating box 9 is connected to the vacuum pump of the pump box 7. A harm eliminating box housing exhaust is connected to the exhaust pipe 24, and the gas leakage detector 21 for exhausting the harm eliminator housing is connected between the harm eliminating box 9 and the exhaust pipe 24. Process exhaust is performed from an exhaust opening of the harm eliminator of the harm eliminating box 9. The gas detector 23 for detecting the breakthrough of the harm eliminator is connected to the exhaust opening of the harm eliminator. The gas sampling port (sample port) 15 is arranged in a room where the gas leakage detection system is installed, and the gas leakage detector 17 for the room atmosphere is connected to the gas sampling port 15. Each of the above-mentioned gas leakage detectors is arranged at each detecting place as many as the number of the kinds of gases that are to be detected at the detecting place. Further, the housing exhaust is performed through the above-mentioned exhaust pipes 10 and 24.
In a conventional system including a semiconductor manufacturing apparatus that consumes a flammable gas and a toxic gas in a manufacturing process of a semiconductor circuit, generally, a place having a possibility of leaking gas, such as a housing covering a process chamber, is forcibly exhausted, and at the same time, gas leakage detection alarm equipment corresponding to the kind of a gas in danger of leaking is installed at a vacuum port.
In addition, generally, the gas leakage detection alarm equipment is installed also in a harm eliminator provided to a semiconductor manufacturing apparatus system. That is, since the harm eliminator is filled with a medical agent for eliminating a harmful substance in an exhaust gas, the gas leakage detection alarm equipment is installed also for detecting a breakthrough point. The breakthrough point refers to a point where the medical agent that absorbs and eliminates a harmful substance is saturated and not able to abate the harmful substance any more.
Further, generally, it is difficult for a current gas leakage detector and a current breakthrough detector to detect a gas that is stable and hard to be decomposed. Thus, a secondary detection or the like in which detection is performed after heat decomposition occurs, is performed on gases such as PFC, NF3 and the like. The breakthrough detector in the harm eliminator samples a gas mainly from a dry atmosphere. Accordingly, there is a problem in that the breakthrough detector may not be able to detect a kind of a gas that is to be detected after hydrolysis is performed.
Further, as gases that are to be detected after hydrolysis is performed, there are WF6, BCl3, SiH2Cl2 and the like. WF6 is detected after generating HF by hydrolysis, and SiH2Cl2 is detected after generating HCl in a similar manner.
Additionally, in the detection of gas leakage in a dry atmosphere as mentioned above, there is another problem in that a stable operation is difficult since an internal liquid of a sensor that is included in the breakthrough detector decreases significantly.
Furthermore, as for the entire conventional semiconductor manufacturing apparatus system using many kinds of gases, there is another problem in that there are many control items since, as mentioned above, the gas leakage detection alarm equipment is required for each kind of gas that is a detection object.
Additionally, in the above-mentioned gas leakage detection alarm equipment, there is another problem in that labor hours and management expenses increase, since not only checks such as a daily check, a periodic calibration and an alarm test are required, but also the number of control items reaches several hundred in a factory manufacturing semiconductor circuits.
In these days, along with the diversification of the kinds of gases used in the semiconductor manufacturing system, new kinds of gases are also developed. However, the development of the corresponding gas detector has not caught up yet, and data of an interference gas similar to a gas that is the detection object have not been sufficiently obtained. Accordingly, in the conventional gas detector, there is another problem in that various unexpected problems may occur.
In addition, the SiH4 detector and the CiF3 detector can detect a plurality of gases with a single detector. Such detection is called representative detection and has an advantage in that a single detector can detect the kinds of gases that have coherency. In other words, the SiH4 detector can detect hydrides such as SiH4, PH3, Si2H6, B2H6 and ASH3, and the CiF3 detector can detect halogenides such as CiF3, Cl2, HCl, HF and BCl3, and O3.
However, in the above-mentioned representative detection, it is impossible to selectively detect kinds of gases and to specify the kinds of gases that are detected. Additionally, since the gases that are targets of the representative detection have a property of easily reacting to an oxidant, NOx and the like included in the air, there is another problem in that detecting leakage of the gases is subject to interference by the air. Further, the acceptable concentration differs depending on the kind of a gas that is the detection target. However, only one reference set value can be set for determining leakage. Thus, there is another problem in that it is difficult to set the set value.